Opening device for opening a bag section of a film web in a bag filling plant

ABSTRACT

The invention relates to an opening device ( 10 ) for opening a bag section ( 210 ) of a film web ( 200 ) in a bag filling plant ( 100 ) for filling in bulk goods, comprising a suction device ( 20 ) for suctioning the two sides ( 212, 214 ) of the bag section ( 200 ) with an articulately supported first suction cup ( 22 ) on the first side ( 212 ) of the bag section ( 210 ) and an articulately supported second suction cup ( 24 ) on the second side ( 214 ) of the bag section ( 200 ), with at least one of the suction cups ( 22, 24 ) being arranged acute-angled in reference to the respective side ( 212, 214 ) of the bag sections ( 200 ).

The present invention relates to an opening device for opening a bagsection of a film web in a bag filling plant for filling with bulkgoods.

In general it is known that bag filling plants are provided for fillingbag sections of a film web with bulk goods. Here, the film web isembodied in several layers, so that two side layers are provided. In afilling station of a bag filling plant a bottom seam of the bag sectionis already provided, so that this bag section is only open towards thetop. A funnel is inserted into this upper opening of the bag section inorder to insert the bulk goods into the inside, thus the intermediatespace between the two side layers, of the bag section.

In order to allow the secure insertion of the funnel and the bulk goodsit is required to open the two sides and/or the two side layers of thebag section and this way provide an appropriate opening section. This isperformed in bag filling plants of prior art by suction devices, whichcomprise at least two suction cups at the two sides of the bag section.

In bag filling plants of prior art and opening devices of prior art itis disadvantageous that the suction device is not operating in an idealfashion under all operating conditions. For example, it may occur thatthe two suction cups contact the respective side of the bag section atboth sides under a vacuum, however for the subsequent motion of therespective suction cup towards the outside the bag section fails to getentrained. This may be caused by different reasons. For example, bygenerating static charge between the two sides and/or side contacts ofthe bag section here increased adhesion may be given between these twosides of the bag section. It is also possible that other negativeinfluences lead to an increased connection of the two sides to eachother within the bag section. In such cases a subsequent attempt, thus asecond trial, must occur for the suction device opening the bag section.This requires accordingly more time, extending the clock time of thisstation, and thus the processing speed of the entire bag filling plant.

The objective of the present invention is to at least partially correctthe above-described disadvantages. In particular, the objective of thepresent invention is to improve the opening of the bag section in acost-effective and simple fashion and particularly to shorten the clocktime by reducing the occasions of faulty suction.

The above-stated objective is attained in an opening device with thefeatures of claim 1. Additional features and details of the inventionare discernible from the dependent claims, the description, and thedrawings. Here, of course, the features and details described in thecontext with the opening device according to the invention also apply inthe context to the dependent claims according to the invention and viceversa, so that with regards to the disclosure here alternating referenceis made and/or can be made to the individual aspects of the invention.

An opening device according to the invention is embodied for opening abag section of a film web in a bag filling plant to be filled with bulkgoods. For this purpose, the opening device according to the inventioncomprises a suction device for suctioning the two sides of the bagsection with an articulately supported first suction cup to the firstside of the bag section and an articulately supported second suction cupto the second side of the bag section. The opening device according tothe invention is characterized in that at least one of the suction cupsis arranged at an acute angle in reference to the respective side of thebag section.

According to the invention the filling with bulk goods occurs in afilling station of the bag filling plant. The bag filling plant is hereembodied e.g., according to the form, fill, and seal (FFS)-method. Forthis purpose, a film web is essentially continuously rolled off a supplyroll. A conversion of the continuous advance of the film web into acycled advance occurs via a buffer device, which may be embodied as acompensation device. Subsequently, a plurality of stations may beprovided for processing the film web. For example, such stations may bea bottom sealing station with a cutting device, filling stations, a headsealing station, as well as a head seam-cooling station. The motionbetween the individual stations occurs via claw devices in a shuttleservice.

A film web in the sense of the present invention is particularlyembodied in two layers as a film tube. Accordingly, two side layers areembodied, which include an intermediate space between them. The bagsection is cut to length, e.g., in a bottom sealing station, in which bya cutting device the individual bag sections are brought into theirrespective length. Simultaneously, a bottom seam is sealed in thisbottom sealing station, in order to close the respective bag section atthe bottom. An opening device according to the invention is preferablyused in a filling station of the bag filling plant.

As already explained, the bag section is transported e.g., with the helpof claw devices into the filling station of the bag filling plant. Here,the two sides and/or the two side layers of the bag section of the filmweb must be separated from each other in order to allow and/or enableinserting a funnel. This occurs with the help of the suction device. Inan embodiment of prior art it comprises two suction cups, which arearranged at the two different sides of the bag section. Upon the arrivalof the bag section in the filling station the two suction cups are madeto approach the two sides of the bag section. Subsequently, a vacuum isapplied via the suction cups, which particularly transfer a vacuum viathe respective suction opening of the respective suction cup to the bagsection and/or to its side. This way, a force towards the outside isapplied upon the respective side of the bag section in order to separatethese two sides and/or the two side layers of the bag section from eachother. As soon as the two sides of the bag section have been suctionedby the respective suction cup, preferably a contrary motion of therespective suction cup occurs towards the outside such that the twosides are separated from each other and an opening develops between thetwo sides and/or the two side layers of the bag section. Now a funneland/or directly the bulk goods can be inserted into this opening.

By the position of the suction device, particularly the two suctioncups, an opening device is embodied for an explicit positioning of thebag section. Within the scope of the present invention the relativepositioning is discussed between the respective suction cup and therespective side of the bag section. This relates here to the bag sectionand the side of the bag section as well as the position of the bagsection and/or the position of the respective side of the bag sectioninside the opening device. In other words, by the opening device arespective correlation is defined to the position of the respective sideof the bag section inserted into the opening device and positioned hereaccordingly. During the operation of the opening device accordingly thebag section with the respective sides is at this position such that thelocal correlation is given in the manner according to the invention.

Advantageously, now an explicit embodiment is given for at least one ofthe two suction cups. Namely, it is arranged at an acute angle inreference to the respective side of the bag section. When now a vacuumis applied via this suction cup, here no homogenous suctioning occurs ofthe respective side of the bag section. Rather, by the acute-angledarrangement one edge of the suction cup will be arranged closer to theside of the bag section than the opposite edge of the suction cup. Thecloser the suction cup is arranged to the side of the bag section thegreater the effect of an appropriately applied vacuum. This leads to thefact that suctioning of the side occurs no longer homogenously over theentire suctioned area of the suction cup. Rather, the start of thesuctioning process occurs no longer in a planar fashion but preferablyin the area of a small section and/or directly at the edge of therespective suction cup, which is arranged closer to the side of the bagsection. Subsequently, after the first opening motion in this suctionarea, the opening motion continues wavelike along the suction cup and/oralong the suction area. This quasi leads to the side being peeled offthe opposite side of the bag section.

By the embodiment according to the invention here the suction force isapplied without any variation and/or enhancement upon a smaller suctionarea. This leads to the fact that the same suction force, due to thereduced area impinged, leads to an improved separating effect and/or anincreased impact of force upon the respective side of the bag section.By the simple and primarily cost-effectively implemented geometriccontacting at an acute angle of the respective suction cup, here usingthe same embodiment of the respective suction cups and the correspondingvacuum system and particularly also the same or essentially the samevacuum, an improved separating effect can be yielded by the describedpeeling function for both sides of the bag section.

Here, it is decisive that the acute-angled arrangement is particularlyassumed in the position of the suction cups which are arrangedparticularly close to the side of the bag section. This particularlyrelates to the suction position as described in greater detail in thefollowing.

By the targeted local reinforcement of the suction force, even indifficult separating conditions, thus particularly under increasedsituations of force between the two sides, which may be generated bystatic charge, here a secure peeling and/or opening of the bag sectionis possible. This way, the risk of any events of faulty suction can bereduced, so that respective delays in the cycle can also be reduced withregards to their probability of occurrence. The entire cycle time ofthis filling station and thus the entire operating velocity of the bagfilling plant are considerably improved this way.

In general, according to the invention any arbitrary alignment of theacute angle is possible for the acute-angled arrangement. In particular,different angular directions may be combined with each other. Thisparticularly relates to an angular arrangement in the top view and/or inthe side view. Accordingly, particularly angular alignments may form ashorizontal angles, thus as angles which extend in the horizontal leveland/or as vertical angles and accordingly as angles in the verticallevel. Here, a combination of horizontal angles and vertical angles in adual-angular alignment is also possible in the present invention.

In the opening device according to the invention it may be advantageousfor the suction cups to be supported in an articulate fashion between asuction position and an opening position. Here, the acute-angledarrangement of at least one suction cup is embodied for the suctionposition. As already mentioned, the suction cups are in an articulatebearing arrangement in the opening device. They may be shuttled betweenthe opening position and the suction position. A minimum distance isgiven in the suction position between the respective suction cup and theside of the bag section. Here, suctioning occurs, as explained above,particularly by the peeling off-effect. When the suctioning has occurredsuccessfully, the suction cups move into the opening position and hereentrain the respective side of the bag section. The acute-angledarrangement is here of particular importance with regards to thefunctionality according to the invention, particularly in the suctionposition. Accordingly, it is decisive in general that at least in thissuction position the respective suction cup assumes this acute-angledarrangement. This leads to the advantages according to the invention.

If with regards to greater freedom in design a different angulararrangement is advantageous or even a parallel embodiment of therespective suction cup in other positions, particularly in the openingposition, this may be easily combined with an effect of the openingdevice according to the invention.

It may also be advantageous when in an opening device according to theinvention the suction cups each show a suction area, which respectivelydefines a suction level. Here, the sectional line generated by theacute-angled arrangement extends between the respective suction leveland the respective side of the bag section vertically or essentiallyvertically. A suction cup comprises preferably a suction opening andaccordingly also a suction area, which by the suctioning effect may alsocome into contact with or into proximity of the side of the bag section.This suction area is preferably embodied in an essentially planarfashion and accordingly defines a suction level, which extends unlimitedbeyond the suction area. The bag section may also show an essentiallyplanar and level extension so that particularly a straight line developsas the sectional line between the suction level and the respective sideof the bag section. The vertical or essentially vertical arrangement ofthis sectional line means that the alignment in an acute-angled fashionoccurs for the respective suction cup essentially exclusively with ahorizontal angle. Here, the horizontal angle shall be understood as anangle which is exclusively measured in the horizontal level. Thisangular alignment is ideally discernible in the top view, which istherefore aligned directly to the horizontal level. Of course, acombination with a vertical angle may also be provided, as explained ingreater detail in the following paragraph. By the vertical progressionof the sectional line a lateral edge of the suction cup, also arrangedessentially vertically, will show the shortest distance from the side ofthe bag section and thus from the start of the peeling off-processbeginning at the respective side of the bag section. The verticalextension is here particularly an extension along or essentially alongthe lines of gravity. This shall be understood as the vertical extensionof the sectional line as well as the perpendicular extension inreference to the base of the corresponding bag filling plant.

Another advantage is the fact that in an opening device according to theinvention the suction cups show one suction area each, whichrespectively define a suction level. Here, the sectional line generatedby the acute-angled arrangement between the respective suction level andthe respective side of the bag section form an acute angle in referenceto the vertical. Here, vertical is also understood as the alignmentpreferably along the line of gravity. Additionally, the vertical is alsoembodied particularly perpendicular in reference to the base of the bagfilling plant. This embodiment is the dual-angular embodiment of therespective suction cup. Here, a combination between a horizontal angleand a vertical angle is provided such that the respective angularalignment is discernible both in the top view as well as in the sideview of the respective opening device and thus the suction device. Thisdual-angular alignment particularly leads to the fact that the minimumdistance between the suction cup and the adjacent side of the bagsection can be reduced to an even smaller area. In particular, thissection acts essentially punctually so that not only an edge of thesuction cup but a corner of the suction cup shows the minimum distance.The trigger section, which shall be understood as the first impact areaof the suction force, is here even further reduced so that accordinglythe same force is applied upon a reduced area. This leads to a furtheramplification of the impact of force and accordingly to an even betterseparating behavior of the two sides of the bag section from each other.

Additionally, it is advantageous when in an opening device according tothe invention both suction cups are arranged at an acute angle inreference to the respective side of the bag section, particularly in amanner symmetrical in reference to the bag section. Preferably, here theacute angularity and thus the corresponding advantages are provided forboth suction cups. This way the peeling off-process is started at bothsides. By the symmetric or also essentially symmetric embodiment withregards to the acute-angled arrangement of the two suction cups thestart of the separation wave occurs, as already explained, for bothsides of the bag section in the same or essentially the same fashion.This way, here too a simpler and/or more cost effective production ofthe suction device can be yielded.

Another advantage is given when in an opening device according to theinvention the minimum distance between the respective suction cup andthe side of the bag section is identical or essentially identical forboth suction cups. The minimum distance has already been mentionedrepeatedly and defines the shortest distance between a section of thesuction cup and the side of the bag section. By the acute-angledalignment this minimum distance is the only angular alignment of thesuction cup arranged over an edge of the suction cup and in adual-angular alignment in a punctual area of the suction cup, thus acorner. When for both sides and thus for both suction cups this minimumdistance is identical or essentially identical, here by identicalselection of the vacuum for the two suction cups a similar or evenidentical situation of impacting force results for both sides of the bagsection. Here, inequality of forces is avoided so that an even increasedsecurity can be provided for the opening process of the bag section. Ofcourse, the same minimum distance may also be used at different angulararrangements of the suction cups in order to yield the same start ofseparation with different separating speeds.

Another advantage is achieved when in an opening device according to theinvention the suction device comprises an adjustment device foradjusting the acute-angled alignment of at least one suction cup.Accordingly, a variation of the respective acute angle can be providedfor the respective suction cup. This way, an adjustment is possible todifferent film materials. In particular, an adjustment to differentthicknesses or different risk situations is possible with regards tostatic charge of the film web.

It is also advantageous when in an opening device according to theinvention at least one of the suction cups shows at least one sealinglip embodied for sealing towards the side of the bag section. Thesealing lip is embodied e.g., from a rubber material or another elasticmaterial. It is geometrically correlated such that in the suctionposition of the suction cups sealing occurs by the sealing lipcontacting the respective side of the bag section. This way, sealing isyielded towards any ventilation of secondary air. This sealing lip is atleast provided at one side of the suction cup, preferably at two orthree sides of the suction cup.

Preferably, at least one side edge of the suction cup is embodied freefrom the sealing lip, so that from here the vacuum can be generated forair to be resupplied. This further amplifies the suction effect by adefined air flow between the suction cups and the side of the bagsection.

In one opening device according to the above-stated paragraph it may befurther advantageous when the sealing lip compensates or essentiallycompensates the acute-angled arrangement of the respective suction cupto the side of the bag section. In other words, the sealing lip contactsor essentially contacts the side of the bag section in a parallelfashion. This way, sealing is yielded by the sealing lip preferably overthe entire suction area of the suction cup. Lateral sealing lips mayhere be embodied with different depths, while a sealing lip mounted atthe top shows a diagonal edge in order to allow compensation and thusparallel alignment to the respective side of the bag section.

It may also he advantageous when in an opening device according to theinvention every suction cup is provided with a suction opening, which isembodied with a grid structure against suctioning in the bag section.Here, the suction opening shows a plurality of individual suctionopenings, which by the grid structure provide minimized individualsuction areas. The suctioning in of the bag section is thereforeprevented so that any jamming of the side of the bag section inside thesuction opening can be avoided. This leads to a further improvement ofthe opening device and particularly also to an acceleration of the cycletime for this opening process.

Additional advantages, features, and details of the invention arediscernible from the following description, in which the exemplaryembodiments of the invention are described in detail with reference tothe drawings. Here, the features mentioned in the claims and thedescription may be essential for the invention individually or in anyarbitrary combination. It shows schematically:

FIG. 1 an exemplary embodiment of the bag filling plant,

FIG. 2 a a bag section prior to the opening process,

FIG. 2 b a bag section of FIG. 2 a after the opening process,

FIG. 3 an exemplary embodiment of an opening device according to theinvention,

FIG. 4 a another embodiment of an opening device according to theinvention,

FIG. 4 b the embodiment of FIG. 4 a in a top view,

FIG. 4 c the embodiment of FIG. 4 b in a side view, distorted,

FIG. 5 a another embodiment of an opening device according to theinvention, and

FIG. 5 b another embodiment of an opening device according to theinvention.

FIG. 1 shows an embodiment of a bag filling plant 100 according to theinvention. In a supply roll, at the right, a film web 200 is wound offcontinuously. A conversion into a cycled advance of the film web 200occurs via a buffer device in the form of a compensation device. In thefollowing, individual stations 170 serve for processing the film web200. Firstly, via a bottom sealing station and a cutting device thebottom seam is generated and the individual bag sections 210 are cut tolength. The respective bag section 210 is transported via claw devicesfrom the right towards the left to the further stations 170. A fillingstation 110 is provided as the next station. Subsequently, a headsealing station and a head seam-cooling station are provided as thestation 170.

An opening device 10 according to the invention is particularly providedat a filling station 110. FIGS. 2 a and 2 b explain the opening processin greater detail. Here, the bag section 210 with its two sides 212 and214 is shown schematically. It is also discernible that the two suctioncups 22 and 24 of the suction device 20 engage the bag section 210 fromtwo different sides 212 and 214.

The direction of motion after the suction process is shown by the twoarrows. Thus, in the position according to FIG. 2 a the two suction cups22 and 24 are in the suction position S, as explained in the followingin the context with FIG. 3. In FIG. 2 b, after the suction process, anopening occurs of the two suction cups 22 and 24 by moving apart suchthat here the bag section 210 opens as well.

FIG. 3 shows in a top view, how an embodiment of an opening device 10according to the invention may be embodied. For example, here the bagsection 210 is discernible in a top view with its two sides 212 and 214.Two suction cups 22 and 24 of a suction device 20 are allocated to thesetwo sides 212 and 214. The cups are capable to generate a vacuum via thesuction area 26 and/or via a suction opening 21, not shown, and toensure suction of the respective side 212 and 214 of the bag section210.

It is also clearly discernible from FIG. 3 that the two suction cups 22and 24, particularly their suction area 26, are arranged angular andparticularly acute-angled in reference to the respective side 212 and214 of the bag section 210. The acute-angled alignment occurs here viathe horizontal angle γ, which in the top view coincides with thehorizontal level and thus the level of the drawing. FIG. 3 also showsclearly the minimum distance A between the respective suction cups 22and 24 and the respective side 212 and 214.

In FIG. 3 the suction device 20 is embodied with two symmetricallyembodied suction cups 22 and 24, When the suction process occurs,suction of the respective side 212 and 214 of the bag section 210 occursin the area of the minimum distance A. Subsequently, via a separatingprocess, preferably in a wavy fashion, this separation process continuestowards the bottom, as shown in FIG. 3, until a complete suction hasoccurred of the two sides 212 and 214 by the suction cups 22 and 24.Subsequently, the two suction cups 22 and 24 are moved out of theirsuction position S into the opening position O, also shown in FIG. 3,and here entrain the suctioned sides 212 and 214 of the bag section 210.This is equivalent to the opening of the bag section 210 as alreadyexplained with reference to FIGS. 2 a and 2 b.

FIGS. 4 a through 4 c show another embodiment of an opening device 10according to the invention. Here, the suction device 20 is shown withregards to one of the two suction cups 22 and 24, namely with regards tothe second suction cup 24. Of course, the opposite first suction cup 22may be embodied in the same fashion. In this embodiment of the suctiondevice 20 a sealing lip 50 is provided for sealing against therespective side 212 and 214 of the bag section 210. Here, too, it isclearly discernible in the schematic partial cross-section that thesuction cup 24 comprises suction openings 21 and a grid structure 23against suctioning in the bag section 210. FIG. 4 a shows here theopening device 10 in a side view. FIG. 4 b shows the top view with hereagain the horizontal angle γ being discernible for the acute-angledarrangement, Additionally, it is clearly discernible that thisacute-angled arrangement with the horizontal angle γ is compensated bythe sealing lip 50 such that, in spite of this acute-angled arrangement,the sealing lip 50 contacts the bag section 210 continuously andparallel at the side 214. FIG. 4 c, which also shows a cross-section,here in a view from the bottom, shows circumferential sealing lips 50 atthe top and left and right at the respective suction cup 24. Here too,again, the compensating effect for the horizontal angle γ by the sealinglip 50 is clearly discernible. However, in this illustration, analternative embodiment of the suction cup 24 is discernible, becausehere the suction openings 21 vary with regards to their size by analtered grid structure 23. Here, it is also clearly discernible that asuction level 28 is defined by the suction area 26.

FIGS. 5 a, and 5 b show two other embodiments, particularly contactingoptions for the suction device 20. FIG. 5 a shows the only contactingvia a horizontal angle γ. This leads to the fact that an intersectionforms 30 between the suction level 28 and the side 212 of the bagsection 210, which extends vertically and/or horizontally. Thissectional line 30 depends accordingly on the angular arrangement of therespective suction cup 22 and 24. FIG. 5 b shows a dual-angulararrangement so that here not only a horizontal angle γ but also avertical angle β provides an acute arrangement. Accordingly, thealignment of the suction level 28 also changes such that now thesectional line 30 extends at an acute angle α in reference to thevertical V. This therefore represents a dual-angular alignment and thusto another reduction of the impact of force upon a punctual area.

The above-stated explanation of the embodiments describes the presentinvention exclusively within the scope of examples. Of course,individual features of embodiments, to the extent technicallybeneficial, may be freely combined with each other without leaving thescope of the present invention.

LIST OF REFERENCE CHARACTERS

-   10 Opening device-   20 Suction device-   21 Suction opening-   22 First suction cup-   23 Grid structure-   24 Second suction cup-   26 Suction area-   28 Suction level-   30 Sectional line-   50 Sealing lip-   100 Bag filling plant-   110 Filling station-   170 Station-   200 Film web-   210 Bag sections-   212 Side of the bag section-   214 Side of the bag section-   A Minimum distance-   S Suction position-   O Opening position-   V Vertical-   α Angle in reference to the horizontal-   β Vertical angle-   γ Horizontal angle

1. An opening device (10) for opening a bag section (210) of a film web(200) in a bag filling plant (100) for filling in bulk goods, comprisinga suction device (20) for suctioning the two sides (212, 214) of the bagsection (200) with an articulately supported first suction cup (22) onthe first side of the bag section (210) and an articulately supportedsecond suction cup (24) on the second side (214) of the bag section(200), characterized in that at least one of the suction cups (22, 24)is arranged acute-angled in reference to the respective side (212, 214)of the bag section (200).
 2. An opening device (10) according to claim1, characterized in that the suction cups (22, 24) are supportedarticulately between a suction position (S) and an opening position (O),with the acute-angled arrangement of at least one suction cup (22, 24)being embedded at least in the suction position (S).
 3. An openingdevice (10) according to claim 1, characterized in that the suction cups(22, 24) each show a suction area (26), respectively defining a suctionlevel (28), with the sectional line (30) generated by the acute-angledarrangement extending vertically or essentially vertically between therespective suction level (28) and the respective side (212, 214) of thebag section (210).
 4. An opening device (10) according to claim 1,characterized in that the suction cups (22, 24) each show a suction area(26), which respectively defines a suction level (28), with thesectional line (30) generated by the acute-angled arrangement comprisingan acute angle (α) in reference to the vertical (V) between therespective suction level (28) and the respective side (212, 214) of thebag section (210).
 5. An opening device (10) according to claim 1,characterized in that both suction cups (22, 24) are arrangedacute-angled in reference to the respective side (212, 214) of the bagsection (210), particularly in a manner symmetrical in reference to thebe section (210).
 6. An opening device (10) according to claim 1,characterized in that the minimum distance (A) between the respectivesuction cup (22, 24) and the side (212, 214) of the bag section (210) isidentical or essentially identical for both suction cups (22, 24).
 7. Anopening device (10) according to claim 1, characterized in that thesuction device (20) comprises an adjustment device for adjusting theacute-angled arrangement of at least one suction cup (22, 24).
 8. Anopening device (10) according to claim 1, characterized in that at leastone of the suction cups (22, 24) comprises at least one sealing lip(50), which is embodied for sealing against the side (212, 214) of thebag sections (210).
 9. An opening device (10) according to claim 8,characterized in that the sealing lip (50) compensates or essentiallycompensates the acute arrangement of the respective suction cup (22, 24)to the side (212, 214) of the bag section (210).
 10. An opening device(10) according to claim 1, characterized in that each suction cup (22,24) comprises a suction opening (21), which is embodied with a gridstructure (23) against suctioning in the bag section (210).